Where to visit between NYC and Chicago?

We are going to visit friends in Manhattan for a few days in August (yes, I know - the heat!) and then driving to visit family in Chicago. We will be in the States for 15 days and, ideally, would like to stop-offs on the way from NYC to Chicago - we're thinking of Niagara Falls and then going the "back way" via Canada to Chicago but don't know where else to stop. The obvious place on the map is Detroit but I get the impression it's not terribly touristy at the moment - does anyone know upstate New York/Michigan/southern Ontario and can suggest a couple of places to visit for a night or two?

My children are 12, 10 and 8. We'll be doing plenty of sightseeing in New York and potentially in Chicago as well so might not particularly want a very museum/gallery-heavy itinerary between the two cities. Thanks

If you're willing to drive a little, West Michigan is lovely. You could go into Canada for Niagara Falls and enter Michigan at Sarnia. Stop at Flint to drink their much talked about water and then drive NW to Glen Arbor.

Route 22, Sleeping Bear Dunes, rent a speedboat on crystal clear lakes, kayaking, Silver Lake dunes for dune buggies and off roading. You can then amble down Lake Michigan to Chicago. There's so much going on there and it's a little different from a lot of UK ideas of a US road trip.

Detroit aside, I'm a huge fan of Michigan. Just not so much in the winters!

Alternatively, if you are theme park fans, there's also Cedar Point in Ohio. You could drive from Niagara straight to Cedar Point, stay overnight for 2 nights in Sandusky and get a full day at the park. It has the biggest roller coasters in the US. I'm not a coaster fan (but my kids are!) and even I had to concede it was much nicer than any other theme park I'd been to.